Same problem here. 11 month old Lewis now believes it is OK to only put his two front paws on the pee pad. He was very accurate up until the past couple months.
I've tried putting a bottle in the middle of his pad for him to aim on, but he doesn't feel the need to 'mark' inside our own home, only outside.
I'm not sure what to do anymore, other than continue to treat him when he gets it right, and to tell him NO when he misses. He can hold his pee in for a good 6-10 hours now, so it's not like I can watch him like a hawk waiting for him to go.
I'm stumped.